Qualitative and quantitative superb vascular imaging in the diagnosis of thyroid nodules ≤10 mm based on the Chinese Thyroid Imaging Reporting and Data System 4 (C-TIRADS 4)

Background

To compare qualitative and quantitative superb microvascular imaging (SMI) and determine the value of SMI in the diagnosis of thyroid nodules (TNs) ≤10 mm based on the Chinese Thyroid Imaging Reporting and Data System 4 (C-TIRADS 4).

Methods

From October 2020 to June 2022, 106 patients with 109 C-TIRADS 4 (C-TR4) TNs (81 malignant, 28 benign) at the Peking Union Medical College Hospital were included. Qualitative SMI reflected the vascular pattern of the TNs and quantitative SMI was recorded by the vascular index (VI) of the nodules.

Results

The VI was significantly higher in malignant nodules versus benign nodules both in the longitudinal (19.9±11.4 vs. 13.8±10.6, P=0.01) and transverse (20.2±12.1 vs. 11.3±8.7, P=0.001) sections. The area under the curve (AUC) of qualitative and quantitative SMI did not show a statistical difference in the longitudinal {0.657 [95% confidence interval (CI): 0.560-0.745] vs. 0.646 (95% CI: 0.549-0.735), P=0.79} and transverse [0.696 (95% CI: 0.600-0.780) vs. 0.725 (95% CI: 0.632-0.806), P=0.51] sections. Next, we combined qualitative and quantitative SMI to upgrade and downgrade the C-TIRADS classification. If a C-TR4B nodule had VIsum >12.2 or intra-nodular vascularity, the original C-TIRADS was upgraded to C-TR4C. If a C-TR4C or C-TR4B nodule manifested VIsum ≤12.2 and no intra-nodular vascularity, the original C-TIRADS was downgraded to C-TR4A. As a result, 18 C-TR4C nodules were downgraded to C-TR4A and 14 C-TR4B nodules were upgraded to C-TR4C. The new model of SMI + C-TIRADS showed high sensitivity (93.8%) and accuracy (79.8%).

Conclusions

There is no statistical difference between qualitative and quantitative SMI in the diagnosis of C-TR4 TNs. The combination of qualitative and quantitative SMI may have the potential to manage diagnosis of C-TR4 nodules.

Contrast-Enhanced Ultrasound of Primary Squamous Cell Carcinoma of the Thyroid: A Case Report

Introduction: Primary squamous cell carcinoma of the thyroid (ThyPSCC) is an extremely rare aggressive malignancy with a poor prognosis. However, almost no report thus far has investigated the microvasculature of ThyPSCC imaged using contrast-enhanced ultrasound. Case Report: A 59-year-old male patient presented to our hospital with progressively worsening hoarse voice symptoms for 20 days and was diagnosed with left unilateral vocal fold palsy. Ultrasonography revealed a solitary marked hypoechoic thyroid nodule with an unclear boundary in the inferior part of the left lobe. Color Doppler flow imaging showed a poor blood flow signal inside this nodule. Contrast-enhanced ultrasound images showed a persistent low peak enhancement of the nodule from its periphery to its center. The time-intensity curve displayed a wash-in time of 10 s, a time to peak of 37 s, a peak signal intensity of 24.5%, and a wash-out time of 70 s for the thyroid tumor. Finally, left hemithyroidectomy of the thyroid tumor was performed, and histopathologic and immunohistochemical evaluations confirmed the diagnosis of ThyPSCC. Postoperatively, the patient received a combination therapy of chemotherapy, radiotherapy, and targeted therapy, but the patient died 4 months after surgery. Conclusion: Primary squamous cell carcinoma of the thyroid is a rare but aggressive malignancy of the thyroid. Herein, we reported a case of ThyPSCC and its ultrasonography and pathologic findings.